[lgirdwood]

Phase 2 of #11306 (kernel / user-space partition), third part: move the library manager to src/kernel/library_manager. Follows #11398.

Patch

• src/library_manager → src/kernel/library_manager: a pure move. The library manager loads and links library and LLEXT modules, and it holds the kernel half of the lib_manager_free_module() system call (z_impl_/z_vrfy_). None of it runs in a user thread, so it is now built into the sof_kernel library.
  • Kconfig: sourced from src/kernel/Kconfig instead of src/Kconfig. The option values are unchanged.
  • User-space README: lists it with the kernel-only directories, and the system call table has the new path.
  • Host builds: only Zephyr builds the library manager, so they are not affected.

Functional change

None.

• Objects and modules: the objects and the LLEXT modules are unchanged, and every build's .config has the same option values before and after.
• Firmware images: the symbols (name, type and size) and the SYS_INIT() order are identical in every image.
• Link order effects: as in Phase 2 (part 1): add src/kernel and a sof_kernel library, move src/init #11394 and Phase 2 (part 2): move src/idc to src/kernel/idc #11398, link order only changes alignment padding in some sections (LNL, MTL), and the gperf-generated kernel object hash table (wordlist) in the PTL builds with Zephyr userspace.

Testing

• Per commit:
  • Firmware builds: tgl, tgl-h, mtl, lnl, ptl, wcl, nvl, imx8, imx8x, imx8m, imx8m_cm7, imx8ulp, imx95 and qemu_xtensa.
  • Extra CI configurations:
    • native_sim IPC3/IPC4 stub builds;
    • imx93 64-bit;
    • PTL with each userspace overlay;
    • PTL with CONFIG_SOF_USERSPACE_PROXY=n;
    • PTL and MTL with os_linux_overlay.conf;llext_relocatable.conf.
  • Comparisons: objects, LLEXT modules and firmware images, as described above.
  • Cadence xt-clang (RI-2022.10): MTL, PTL and NVL compile.
  • Host: the host library and cmocka build and pass.
• At the tip:
  • all cmocka configurations, the testbench and the tools pass;
  • the platforms that already fail on main (acp_6_0, acp_7_0, acp_7_x, mt8186, mt8188, mt8195, mt8196, mt8365) have unchanged error sets.
• Hardware: ARL-S (MTL firmware, which builds the library manager), sof-arl-hdmi.tplg, comparing Phase 2 (part 2): move src/idc to src/kernel/idc #11398 and this branch.
  • Result: both boot, load the base firmware library, play on HDMI, and play again after runtime suspend, with no DSP errors.
  • Not covered: this topology does not use an LLEXT module, so loading external modules was not exercised on hardware. TGL does not build the library manager.

All of the above was run on 78b23ad with #11394 and #11398 applied. After the rebase onto 414a8a2 (current main, including #11398), the patch is unchanged, and the firmware builds, the host library and cmocka were repeated at the tip.

🤖 Generated with Claude Code

[Copilot]

🔵 Needs a closer look

The component-creation callback remains directly callable from userspace despite being moved into a kernel-only translation unit, so user-side lifecycle callbacks must be separated from privileged loader and syscall code.

No open issues 🎉

What changed in this PR

This PR advances SOF’s kernel/user-space source partition by relocating the library manager under src/kernel and building it into sof_kernel. It also includes the stacked IDC relocation from #11398.

Changes:

• Relocates library loading, linking, notification, and DRAM persistence code.
• Updates CMake and Kconfig wiring for the relocated directories.
• Updates directory classifications and documentation paths.

File	Description
zephyr/​CMakeLists.txt	Removes direct inclusion of the old directories.
src/​kernel/​library_manager/​llext_manager.c	Relocates LLEXT loading and memory-domain management.
src/​kernel/​library_manager/​llext_manager_dram.c	Relocates library-context save and restore logic.
src/​kernel/​library_manager/​lib_notification.c	Relocates external-module notification handling.
src/​kernel/​library_manager/​lib_manager.c	Relocates library loading, lifecycle callbacks, and syscall handling.
src/​kernel/​library_manager/​Kconfig	Relocates library-manager configuration options.
src/​kernel/​library_manager/​CMakeLists.txt	Builds relocated sources through the kernel subtree.
src/​kernel/​Kconfig	Sources IDC and library-manager options.
src/​kernel/​idc/​zephyr_idc.c	Relocates Zephyr inter-core messaging.
src/​kernel/​idc/​README.md	Updates the directory name and documentation link.
src/​kernel/​idc/​Kconfig	Relocates IDC timeout configuration.
src/​kernel/​idc/​idc.c	Relocates inter-core command handling.
src/​kernel/​idc/​CMakeLists.txt	Integrates IDC sources into the kernel subtree.
src/​kernel/​CMakeLists.txt	Adds IDC and library-manager subdirectories.
src/​Kconfig	Routes relocated configuration through kernel Kconfig.
src/​include/​sof/​userspace/​README.md	Updates directory taxonomy and syscall implementation paths.
src/​audio/​README.md	Updates the kernel-only IDC path.
AGENTS.md	Documents src/kernel and its build library.

_{Review effort: Balanced}